Instituto Politécnico Nacional

About: Instituto Politécnico Nacional is a education organization based out in Mexico City, Mexico. It is known for research contribution in the topics: Population & Control theory. The organization has 43351 authors who have published 63315 publications receiving 938532 citations. The organization is also known as: Instituto Politécnico Nacional & Instituto Politecnico Nacional.

Monte Carlo simulation of electron transport in the III-nitride wurtzite phase materials system: binaries and ternaries

Abstract: We present a comprehensive study of the transport dynamics of electrons in the ternary compounds, Al/sub x/Ga/sub 1-x/N and In/sub x/Ga/sub 1-x/N. Calculations are made using a nonparabolic effective mass energy band model. Monte Carlo simulation that includes all of the major scattering mechanisms. The band parameters used in the simulation are extracted from optimized pseudopotential band calculations to ensure excellent agreement with experimental information and ab initio band models. The effects of alloy scattering on the electron transport physics are examined. The steady state velocity field curves and low field mobilities are calculated for representative compositions of these alloys at different temperatures and ionized impurity concentrations. A field dependent mobility model is provided for both ternary compounds AlGaN and InGaN. The parameters for the low and high field mobility models for these ternary compounds are extracted and presented. The mobility models can be employed in simulations of devices that incorporate the ternary III-nitrides.

Review: Educational data mining: A survey and a data mining-based analysis of recent works

Abstract: This review pursues a twofold goal, the first is to preserve and enhance the chronicles of recent educational data mining (EDM) advances development; the second is to organize, analyze, and discuss the content of the review based on the outcomes produced by a data mining (DM) approach. Thus, as result of the selection and analysis of 240 EDM works, an EDM work profile was compiled to describe 222 EDM approaches and 18 tools. A profile of the EDM works was organized as a raw data base, which was transformed into an ad-hoc data base suitable to be mined. As result of the execution of statistical and clustering processes, a set of educational functionalities was found, a realistic pattern of EDM approaches was discovered, and two patterns of value-instances to depict EDM approaches based on descriptive and predictive models were identified. One key finding is: most of the EDM approaches are ground on a basic set composed by three kinds of educational systems, disciplines, tasks, methods, and algorithms each. The review concludes with a snapshot of the surveyed EDM works, and provides an analysis of the EDM strengths, weakness, opportunities, and threats, whose factors represent, in a sense, future work to be fulfilled.

Reliability study of phase-change nonvolatile memories

Abstract: A detailed investigation of the reliability aspects in nonvolatile phase-change memories (PCM) is presented, covering the basic aspects related to high density array NVM, i.e., data retention, endurance, program and read disturbs. The data retention capabilities and the endurance characteristics of single PCM cells are analyzed, showing that data can be stored for 10 years at 110/spl deg/C and that a resistance difference of two order of magnitude between the cell states can be maintained for more than 10/sup 11/ programming cycles. The main mechanisms responsible for instabilities just before failure as well as for final device breakdown are also discussed. Finally, the impact of read and program disturbs are clearly assessed, showing with experimental data and simulated results that the crystallization induced during the cell read out and the thermal cross-talk due to adjacent bits programming do not affect the retention capabilities of the PCM cells.